When metformin was given to animals they displayed reduced symptoms of nicotine withdrawal, and researchers believe the established safety of metformin could help transform these findings into clinical trials.

Previous research has indicated metformin could have many more applications, including boosting treatment for some cancers and dementia, so researchers assessed how it fared in a trial investigating smoking cessation.

Scientists from the Perelman School of Medicine at the University of Pennsylvania and Johns Hopkins Medicine believe metformin has an impact upon a protein called AMPK, located in the hippocampus in the brain.

Long-term nicotine use increases AMPK activity, but this is reversed during nicotine withdrawal, which explains some of the negative symptoms which can occur, such as anxiety.

The researchers concluded that the findings indicate metformin's treatment potential among humans, although human trials will have to be conducted to validate these findings.

"Although we are just beginning to characterize this new role for metformin, our study suggests that the protein it acts on could be a new target for smoking cessation treatment," said senior author Julie Blendy, PhD, a professor of Systems Pharmacology and Translational Therapeutics at Penn.